1. Field of the Invention
The present invention relates to a film winding-up system for a photographic camera, and more particularly to a control system for controlling a display device for displaying the winding-up conditions such as an advance of a film, completion of one-frame winding-up operation and the like in response to a film winding-up operation.
2. Description of the Prior Art
A known film advance condition display system comprising a driven member driven (e.g. rotated) in response to the movement of a film due to the film winding-up operation and a display member for continuously displaying in various manners the film advance conditions in accordance with the driven movement of the driven member is disclosed, for example, in a Japanese utility model application laid open under No. 55-4816.
In this system, the film winding-up conditions are displayed by varying the displaying manners during one-frame winding-up operation in response to the movement of the driven member. However, according to this system, as a liquid crystal display element employed for the camera because of its low power consumption characteristics is relatively slow in reacting, the element often fails to properly respond to the movement of the driven member, thereby making it impossible to properly display the film advance condition. This problem occurs more conspicuously at a low temperature for the temperature characteristic of liquid crystal. Further, since the film advance condition is to be displayed only while the film is being advanced, i.e. during a film winding-up operation, which takes shorter than 1 second, it is difficult for the operator to check or confirm the display.
A Japanese patent application laid open under No. 60-118831 discloses a camera system in which a driven member is operatively connected through a mechanical apparatus to a film frame counter and the film frame counts up the number of exposed frames of the film in response to a film winding-up operation, i.e. a movement of the driven member. According to this system, the mechanical apparatus tends to be structurally complicated and further there is inconvenience that the operator is unable to check or confirm for the proper winding-up operation thereof unless the film is loaded.
The film winding-up system, in general, carries out a one-frame film winding-up operation and also an initial film loading operation. In the latter operation especially, it has been a problem how reliably and simply the camera judges the timing for the operation and then executes and displays the operation.